Many psychotropic drugs exert their clinical effects through actions at postsynaptic receptors for neurotransmitters in the brain. Recently we succeeded in identifying biochemical receptor binding for several neurotransmitters in the central nervous system. We propose to extend these investigations to clarify receptors interactions for dopamine, the norepinephrine beta-receptor and gamma-aminobutyric acid (GABA). These studies may facilitate identification of new psychtropic agents, explicate the mechanisms of action of various drugs, and shed light on abnormalities in mental illness.